coatings on portacabin

[brightspark]

can anyone tell me what the coating is on porta cabins they are made of exterior ply and are coated with a textured finish

 

[Spark plug]

Artex?

 

[WorkshopChris]

What about this.
http://www.mig-welding.co.uk/forum/threads/peeling-paint-on-a-portacabin.63922/#post-818245

 

[Shedendman]

http://www.diynot.com/diy/threads/textured-coating-on-exterior-ply.258936/

Sorts of point in that direction -ish?